1. Field of the Invention
The present invention relates to apparatus and methods for operating a camera system including a fisheye lens, and, more particularly, to apparatus and methods for operating an automotive rear view camera system including a fisheye lens.
2. Description of the Related Art
Automotive rear view cameras often use optical fisheye lens. A fisheye lens is a type of wide-angle lens that produces a very wide, hemispherical image. Like all the ultra-wide angle lenses, fisheye lenses suffer from barrel distortion, especially for extremely wide angles of view, which results in a convex appearance.
An example of a distorted image captured via an automotive rear view camera is shown in FIG. 1. As is typical of the distortion produced by a fisheye lens, the field of view is much wider, e.g., about three times wider, at the top of the image than at the bottom of the image. The reason for this disparity may be that objects at the top of the image are farther away from the lens than are objects at the bottom of the image.
It may be possible to remove the distortion caused by the fisheye lens by using a video Digital Signal Processor (DSP) with SDRAM. However, such employment of a full-blown DSP would be an expensive solution and thus may be considered overkill.
Accordingly, what is neither anticipated nor obvious in view of the prior art is a method of giving the viewer the option of removing distortion from images captured by use of a fisheye lens, and doing so in an inexpensive way.